How To Plan For Memory Expansion On a Linux Host

When it is time to upgrade the memory on a Linux host, it is important to understand the existing memory information of the system, which will help to plan the memory upgrade appropriately without opening server chassis (especially, when you have Linux rack mount server).

What is the current total RAM used in the system?

This can be obtained using free command or from the /proc/meminfo file as shown below. In this example, the current RAM is 1GB.# free Sample output:

How many memory slots are available for expansion?

References:

dmidecode can also be used to identify details about several other hardware related information. dmidecode command reads the systems DMI table for the hardware and BIOS information. DMI stands for Desktop Management interface and SMBIOS stands for System Management BIOS.

You should use either -t or –type, but never -type with single dash (that is indeed incorrect). You can see dmidecode’s help screen by executing it with –help as an argument (alternatively, you can read the manual page: man dmidecode). If you are unsure about what to do then simply execute dmidecode without any arguments at all.